Galvanometer.



f sTATns Pagani- OFFICE. 7

RALPH n. sur, or PARK RIDGE, Ann max c. sronL'rINe, or CHICAGO, ILLINOIS.

GALvANoIInTEn.

'Specification of Letters Patent. i

Patented Iren. 3,1914.

Application led September 9,1912. Serial No. 719,381.

La# The invention-'consists in ,the combinav tions and arrangements of parts hereinafter fullydescribed and claimed. ,The invention will be best understood-by reference to the accompanying drawin mfolnming. a part ofthis specification and 1n Figure' 1 is a front elevation o'fa galvanoineter embodying our .invention shown with the Yfront glass `removed, Fig. 2 is a z5 'horizontal section taken on line --of Fig. 1, and Fig. 3 is a vertical section takenon line fy-fyof 1.x.; 1 A A v I 'The preferred' form jof construction as illustrated in the drawings, comprises 'a lo suitable base 1 supported by means of a permarient lug 2 andlevelingscrews 3 as shown. FAn inc1o'sure'is ;arranged upon basel, the

top, two sides aid 'bottom of 'said inclosure:

being formedo single strip` of sheet metal Belieben-t into rectangular form as shown, 'the ends .5' of saidf'sheet' beingyoverlapped to .form the `lbottom of said inolosure. 'Elie overlapped ends 5 are secured in .position'on basel by means of screws 6 as shown. The o'side portions of strip 4 are extendedv out# lwardly at each edge, as indicated at' 7, and theedges of theseoutwardly extended por- .tions are turned inwardly to form retaining flanges 8 as shown in Fig. 2. lGrlass plates 9' e5 are inserted between corresponding portions Y 7 and behind corresponding flanges v8 "as shown in Fig. 2. formed on the bottom portions 5 andare positioned to rest within the lower portions of the glass plates l0 to retain said plates in position behind flanges 8, the'upper portions of said glass plates being held 1n positionby contact with the edges of the to ,forming portion of strip 4. Each of the g ass plates 65.10 Vis extended somewhat above the top of the inclosure so as to facilitate removal SHY and` Retaining lips 10 are l thereof. AIt will be observed, that when glass plates 10'are inserted in position, they serve to stii'fen and `reinforce the strip 4 as well as" .const1tute a transparentront and rear for the inclosure permitting ready .inspection of the interior` thereof. The. inclosure thus' formed may be economically manufactured', is attractive in appearance and has `sutlicient strength and stiffness for the purpose intended.

\ lA substantially U-shaped support is arranged horizontally in the inclosure abovedescribed, being secured in position therein byme'ans of screwsll passed through the sides osaid inclosure. `The limbportions of said support are providedwith sockets 12 adapted to receive the poles 13 oan ordinary hpermanent horseshoe magnet, said poles being detachably secured in position by means of set screws 14. The bend l5 of said support maybe circular' in form and is provided with a scale as indicated. The

support is alsio provided with depending lug '16tojwhich a'rearwardly extending rod 17 is'secured and a soft iron core 18 is secured to the rear end of rod 17 between the magnet poles 13. An ordinary galvanometer coil 19 `is suspended in 'the inclosure by means of a wire 2O in positionto embrace core 18 as shown. Wire 20 is attached at its endto a metallic strip ,21 which in turn is secured to one'terminal of coil 19, said coil being made of 'insulated wire wound upon a suitable frame. At its 'upper end wire 20 is attached to the lower end of supporting rod 22 which in turn passes throngl 1.a 'perforation `in the .top of the inclosureAn upwardly turned 'lea-,s'pring 23 is secured to the top ofthe inclosure and is perforated to embrace rod '22 and serves as a clampin means for holding Hsaid rod in adjuste positions. Rod

22 alsocarries a stop 24 which is adapted tov contact with the top of the -inclosure to limit: the upward movement of rod 22. By this.

arrangement it will be observed, that coil 19 will beI readily adjusted to proper relation with respect to core 18 for use, or may loweredto rest upon said core when not 1n use. Coil 19 also carries a forwardly -extending indicator inger 25 having its forward Y end bent downwardly o-ver the scale 15 to cooperate with said scale so as to indicate defiections of the coil due to the passage "of a current therethrough, as will be readily understood by lthose skilled in the art.

Coil 19v carries at its lower* end a clamping member 26 which is in electric connection with the other end of said coil and serves as a means for securing the same to the end of a connect-ing wire 27, which leads to a bent conductor rod 28 securedto a binding post 39 asshown. Binding post 29 is insulated from the inclosure and another binding post 30 is secured to the other side of said inclo-sure 'an in electric connection therewith. vSaid binding posts serve as a means for connecting the galvanometer in an electric circuit for testing in the usual manner. By this arrangement it will be observed, that one end of the coil 19 is placed in electric connection with binding post 30 through strip 4, rod 22, wire 20 and strip 21, the other end of coil 19 being in electric connection with the binding post 29,

thus permitting the passage of a current which it is desired to test through said coil.

The galvanometer operates in the usual manner and the operation thereof needs no further description here.

While we have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation and modification without departing from the spirit4 of the linvention. We, therefore, do not wish to be limited to the exact details set forth, but desire to avail ourselves of such variations and modifications as come within the scope 0f the appended claims. v Having described our invention what we claim as new and desire to secure by Letters Patent is: 1. An apparatus of the class described comprising a casing; a substantially U.- shaped support secured in said casing,- each of the limbs of said support being provided with sockets adapted to receive the poles of a magnet and the bend of said support being provided with a scale; a magnet having its poles secured in said socket.; a coil suspended between said poles; and an indicator linger carried by said coil and coperating with l said scale.

2. An apparatus of the class described comprising a. casing; a substantially U- shaped support secured in said casing, each of the limbs of said support being provided with sockets adapted to receive the poles of a magnet and the bend of said support being provided iwith a scale; a magnet having its poles secured in saids'ockets; a coil suspended4 between said poles; a core atindicator linger carried by said coil and cooperating. with said scale.

4. An apparatusof the class describedv comprising a casing; a substantially U- shaped support secured in said casing, each of the limbs of said support-being provided with sockets adapted to receive the poles of a magnet and the bend of said sup ort being provided with al scale; a magnet aving its poles secured in said sockets; a coil adjustably suspended between said poles; a core attached tosaid support and arranged within said coil; and an indicator finger carriedV by said coil and .coperatingwith said scale.

5. A casing comprising a base; a single strip of sheet metal bent to form the top, sides andbottom of an inclosure, the ends of said strip being overlapped to constitute said bottom; screws securing said overlapped ends to said base; inwardly turned flanges at the edgesjof the side portions of said strip; and glass plates inserted behind said fianges to form the front and rear of said inclosure.

G. A casing comprising a base; -a'smgle strip of sheet-metal bent to form the top, sides and bottom of an inclc-sure, the ends of said strip being overlapped to constitute said bottom; screws securing said overlapped ends to said base; inwardly turned flanges -at t-he edges of the side portions of said strip; glass plates inserted behind said flanges to form the front and rear of said' inclosure; andlips on the bottom'portion of said elo-sure resting inside said glass plates; In testimony whereof we have signed our names to this specification' in the presence 'of two subscrlbmg witnesses.

RALPHR. sHAY. MAX c. STOELTING. 

